Valves are commonly used in hydraulic applications. In general terms, the valve is configured to regulate fluid flow by opening or closing fluid passages. Commonly used types are e.g. ball valves, plug valves, and gate valves. U.S. Pat. No. 3,383,088 discloses a plug valve having a conical shaped plug inserted in a conical bore. The space between the inner wall of the bore and the outer surface of the rotating body is sealed by means of a sleeve. Further, pressure relief areas are provided to prevent a pressure build-up forcing the sleeve into a port of the plug. One drawback with the above-mentioned valve is that the manufacturing requires complex and advanced machinery. Another drawback is that the plug is allowed to move in an axial direction during operation, reducing the reliability of the valve. A yet further drawback with the valve is that it may not be implemented in hydraulic applications utilizing an internal pressure above 400 bars. In such case, hydraulic fluid may leak behind the sleeve and completely eliminate the function of the pressure relief areas.
For hydraulic applications, the DN-series of cartridge ball valves are commercially available by Rótelmann GmbH. These valves are configured to be connected to control manifold blocks in a simple way. Such a valve comprises a cartridge for insertion in a prepared well in the control block. The bore, which intersects the cartridge well at right angles, is blocked by means of a ball valve enclosed within the cartridge. An o-ring helically attached to the cartridge seals the cartridge-bore interface.
One disadvantage with the DN-series of valves is that the o-ring must pass over the openings of the cartridge when the valve is mounted. Hence, there is a severe risk of tearing the o-ring during mounting. Further, the valves comprise a plurality of components, leading to a complex and expensive valve.
Hence, there is a need for an improved valve, being efficient and cost-effective.